Multi-dimensional transformation system of direct-shear test instrument of large-sized rock mass structure faces

Abstract

The invention relates to a multi-dimensional transformation system of a direct-shear test instrument of large-sized rock mass structure faces, which comprises n bottom shim plates and n side shim plates, wherein the n bottom shim plates are sequentially superposed from top to bottom according the area size to form a bottom shim plate assembly. The bottom surfaces of samples at the upper part and the lower part of the bottom shim plate assembly contact in a stress way, the lower part of the bottom shim plate assembly contacts with a frame in a stress way, and the centroids of each bottom shim plate, the sample at the upper part and the sample at the lower part are positioned on the same upright straight line; the side shim plates are positioned at the side face of the sample at the lower part and are arranged on steps between the adjacent bottom shim plates and steps between the bottom shim plate at the lowest part and the frame, the top surface of each side shim plate is positioned on the same plane, and the same plane is lower than a connection face between the sample at the upper part and the sample at the lower part; and the side shim plate which is farthest away from the side face of the sample at the lower part contacts with the frame in a stress way. The invention can carry out direct-shear test on the shearing strength of structure faces with different dimensions so as to obtain the change rule and the stable threshold value of the size effect of the shearing strength of the structure faces.

Description

technical field [0001] The invention relates to a multi-scale conversion system of a large-scale rock mass structural surface direct shear tester, which is suitable for measuring the shear strength of a rock mass structural surface with a size of 10cm to 100cm. Background technique [0002] At present, the methods for determining the shear strength of rock structural planes at home and abroad mainly include direct shear test method, indoor model test method and empirical estimation method. The method of comprehensively obtaining the shear strength of structural planes through direct shear tests combined with engineering geological survey data is commonly used by rock mechanics workers in China. However, there is a size effect on the shear strength of the structural plane of rock mass, that is, as the size of the structural plane increases, its shear strength tends to decrease. In order to obtain the stable shear strength of the rock mass discontinuity plane, it is necessary...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the invention is to solve the shortcoming that the existing direct shear test instrument can only measure the shear strength of the rock mass structural surface of a single sample. The invention provides a kind of rock mass structural surface direct shear test instrument (or called a direct shear instrument) The multi-scale conversion system, using this system, can conduct direct shear tests on the shear strength of structural surfaces at different scales, and then obtain the change law and stability threshold of the size effect of structural surface shear strength

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